Investigation of the Barrier Heights for Dissociative Adsorption of HF on SiC Surfaces in the Catalyst-Referred Etching Process

Abstract

We have developed a novel abrasive-free planarization method, which we term catalyst-referred etching (CARE). In silicon carbide (SiC) CARE, Pt is used as a catalyst and HF solution is used as an etchant. CARE produces a crystallographically undamaged and smooth SiC surface. To understand the removal mechanism at the topmost surface of SiC in the CARE process, we performed first-principles reaction path simulations using the simulation tool for atom technology (STATE) program package. These calculations are based on the density functional theory within the generalized gradient approximation of Perdew et al. The barrier height of the dissociative adsorption of HF on a SiC surface was evaluated by the climbing image nudged elastic band method. We present simulation results for the initial stages of the etching process. The reaction barrier height for adsorption of the first HF is 1.2 eV.